This is the philosophical heart of your search. A single book cannot be complete because the concept of devils and demons is living folklore. Every culture invents new demons, every horror movie adds a new name, and every TTRPG supplement (like Dungeons & Dragons’ Mordenkainen’s Tome of Foes ) adds a dozen more.
Note: When searching for digital copies, please respect copyright laws and consider purchasing the physical book from secondhand bookstores or digital retailers to support the preservation of mythological studies. the complete book of devils and demons pdf upd
